1. Technical Field
The present invention relates to an illuminant device comprising lamp clips for holding lamps and to the lamp clip.
2. Description of Related Art
A liquid crystal display is made by lamination of a liquid crystal display panel and an illuminant device in which a plurality of rod-shaped lamps are juxtaposed on a chassis substantially parallel to each other with both end parts thereof being held respectively. Here, both end parts of the lamps are fixed by lamp holders which are disposed at both lateral parts of an illuminant devices for example.
In recent years, with the increase in the size of a liquid crystal display, the number of lamps in an illuminant device tends to increase and each lamp tends to get longer and thinner.
Regarding the increase in the number of lamps, an illuminant device, in which lamps are arranged densely at a central side in a lamp juxtaposition direction and thinly at both end sides in the lamp juxtaposition direction, has been proposed with the aim of maintaining required luminance while depressing uneven luminance of an illuminant device so as to reduce the number of lamps (see Japanese Patent Application Laid-Open No. H6-75216 (1994)).
In the above illuminant device, a plurality of lamps are juxtaposed in such a manner that a pitch gradually increases from a central part in a juxtaposition direction toward both end parts in the juxtaposition direction. Accordingly, luminance is the highest in a central part of a screen of a liquid crystal display panel and gradually lowers toward both end parts of the screen. By decreasing the number of lamps as described above, low power consumption, miniaturization, thinning and weight saving are achieved.
On the other hand, regarding elongation of a lamp, an illuminant device, which is provided with not only lamp holders for holding both end parts of lamps but also lamp clips for holding at least one point or two points of a central part of lamps, has been proposed with the aim of holding elongated lamps reliably and maintaining the performance, quality or the like of an illuminant device (see Japanese Patent Application Laid-Open No. 2001-210126).
In the meantime, when one lamp clip having one holding portion for holding one lamp holds one lamp, there is a problem that the number of lamp clips increases and the number of working steps for holding lamps with lamp clips increases.
In order to solve the above problem, disclosed in Japanese Patent Application Laid-Open No. 2001-210126 is a lamp clip which integrally has a plurality of holding portions for respectively holding a plurality of adjacent lamps.
When such a lamp clip is used, it is possible to hold a plurality of adjacent lamps simultaneously and it is therefore possible to decrease the number of lamp clips and the number of working steps related to lamp clips. In particular, when four lamps are juxtaposed, for example, it is only necessary to prepare two lamp clips, each of which integrally has two holding portions for respectively holding two adjacent lamps, and perform a holding operation of a lamp two times.
Especially, the lamp clip disclosed in Japanese Patent Application Laid-Open No. 2001-210126 is formed in a circular notch grip shape having an opening at a part, made of a flexible transparent member and integrally molded for one tube or multi tubes, so that a lamp can be protected, a high degree of positional accuracy of lamp alignment can be ensured, uneven luminance at information display surface can be prevented, and the effect of the shadow of a lamp holder on luminance lowering or uneven luminance of information display surface can be prevented by employing transparent material.
In the meantime, when a plurality of lamps are juxtaposed with different pitches as disclosed in Japanese Patent Application Laid-Open No. H6-75216 (1994) and the lamps are held by lamp clips disclosed in Japanese Patent Application Laid-Open No. 2001-210126, a possible structure is that all lamp clips are located to have a staggered arrangement, with one lamp clip corresponding to one lamp. The staggered arrangement here means that lamp clips adjacent in the juxtaposition direction of lamps are arranged in different positions in the longitudinal direction of the lamps. The same arrangement will be hereinafter referred to as a staggered arrangement.
However, such a structure has a problem that the number of lamp clips increases and the number of working steps for holding lamps with lamp clips increases.
Therefore, a possible structure is that all lamp clips are located to have a staggered arrangement, with one lamp clip corresponding to two lamps.
In this case, since the juxtaposition pitch of lamps is not constant, a wide variety of lamp clips having different separation distances of two holding portions must be prepared in correspondence to a wide variety of juxtaposition pitches.